Spill-Resistant Reclosable Closure Assembly for a Lid

ABSTRACT

A closure assembly comprising a multi-function closure tab cooperatively mated to a lid wherein said closure assembly provides a selectively reclosable spill-proof closure device and a spill-resistant vent device, and wherein said closure tab provides an integral means to allow said closure tab to be securely locked to itself in an alternative open position. The lid includes a drinking hole of arbitrary size, shape and placement, and includes a means for attaching the closure tab to said lid. The closure tab includes a plug for sealing and resealing the drinking hole, a means for attaching the closure tab to the lid, a lifting tab to manipulate the closure tab to open and close the lid, and provides a plug holder to secure the plug to the closure tab itself when in the open position. The mating of the closure tab to the lid cooperates to provide said spill-resistant vent device. While the invention has many potential applications, it is especially suitable for use in a disposable beverage cup lid.

BACKGROUND

1. Field of Invention

The invention is a closure assembly for a container lid wherein said closure assembly provides a selectively reclosable spill-proof closure device and a spill-resistant vent device.

2. Description of Prior Art

The prior art shows many designs for container lids that might be used as disposable beverage cup lids. The dominant commercially viable designs are known as “tear-back” lids, for example as shown by U.S. Pat. No. 5,699,927, and “always open” lids, for example as shown by U.S. Pat. No. 4,589,569. Said designs are variously embodied as essentially “flat” lids, for example as shown by U.S. Pat. No. 5,111,961, or “domed” lids, for example as shown by U.S. Pat. No. 5,839,601.

While some known designs such as “tear-back” lids are initially sealed, the prior art shows few practical lids that have a completely and reliably reclosable drinking hole. It is well known that it is extremely desirable to be able to easily and reliably reclose beverage containers to prevent spillage of container contents (such as hot coffee), particularly in circumstances such as consuming a beverage while operating a motor vehicle or while walking. Furthermore, it is desirable that such reclosable lids be easy to open and close with one hand, strictly by feel without visual reference. Some known designs have attempted to fulfill these objectives, for example as shown by U.S. Pat. No. 6,679,397, U.S. Pat. No. 4,899,902 and U.S. Pat. No. 6,644,490. In this regard, all known designs have proven to be unsatisfactory for various reasons.

As shown by U.S. Pat. Application No. 20030089714, it is possible to provide a reclosable beverage cup lid by incorporating a separate closure tab device. The functional elements of said closure tab device, namely a plug, a flexible stem, and a means for mounting the tab to a lid, are well known from many other closure designs. In this particular design the plug lock-back means (plug holder) is provided by a separate means on the lid body diametrically opposite to the drinking aperture. This design requires a long tab to reach the plug holder that makes it difficult to manipulate the closure tab to open and close the lid with one hand because of the distance that the plug has to be moved. Additionally, because of the flexibility of the long stem of the tab, it is difficult to align the plug with the plug holder without visual reference. The embodiment of a plug holder opposite the drinking hole furthermore greatly reduces the clear area of the lid body that might otherwise be used for advertising or branding purposes. This design incorporates a spill-resistant vent device that operates by the inherent surface tension of liquid constrained between two closely spaced surfaces. While this may be adequate for minor splashing, there is no provision for constraining significant volumes of liquid if a cup is placed on its side for more than an instant.

It is well known that to prevent the excessive generation of foam or froth during the consumption of carbonated beverages such as beer, there exists a requirement that the drinking hole in a lid be substantially larger than that found in most lid designs. Most known reclosable lids designs cannot be embodied with arbitrary drinking hole placement, size and shape to suit various liquids or user preferences.

It is a common deficiency that most lids that incorporate vent holes are subject to leakage through said vent holes.

While some known lid designs are in some aspects functionally adequate, said designs require non-standard beverage cups, for example as shown by U.S. Pat. No. 6,056,144, thus rendering said lids commercially impractical.

Many known reclosable lids are relatively complex, and are consequently difficult and expensive to manufacture, for example as shown by U.S. Pat. No. 5,706,972.

Many known lids don't nest or stack well for efficient packaging.

It is clearly shown from the prior art that all known lids suffer from many shortcomings, including those set out above.

SUMMARY OF INVENTION

The invention is a closure assembly comprising a closure tab mated to cooperating parts of a lid, wherein said closure assembly provides a selectively reclosable spill-proof closure device and a spill-resistant vent device, and wherein said closure tab provides an integral means for securing one part of said closure tab to another part of said closure tab. The cooperating parts of the lid comprise: a means for cooperatively mating the said lid to the closure tab; and an aperture of arbitrary size, shape and placement. The closure tab comprises: a plug for sealing the lid aperture; an attachment means for cooperatively mating said closure tab to the lid; a lifting tab to manipulate said closure tab between an open and closed position; and a plug holder means for securing the plug to another part of said closure tab to hold the plug away from the lid aperture. The spill-resistant vent device is provided by the cooperative mating of the attachment means of the closure tab and lid. While the invention has many potential applications, it is especially suitable for use in a disposable beverage cup lid.

Note: The section headings below are provided for convenience only and do not limit the content or meaning of said sections. Text that is emphasized relates to defined parts of the invention. If the meaning of an emphasized item is not obvious, then generally the first occurrence of said item defines its meaning or its relationship to other previously defined terms. The term cup refers generically to any type of cup or container for liquids. The terms horizontal and vertical are used with respect to a cup and lid in the normal upright position.

OBJECTS AND ADVANTAGES OF THE INVENTION

It is an object of the invention is to provide, without functional or economic compromise, a practical reclosable closure assembly for a lid that is suitable and cost-effective for use in a disposable beverage cup lid. As is shown by the prior art, and as is shown in current commercial practice, no known closure satisfactorily fulfills this objective.

The Closure Assembly

It is an object of the invention to provide a closure assembly that is easily, completely, and reliably reclosable, thus making said closure assembly spill-resistant or spill-proof.

It is an object of the invention to provide a closure assembly that is easy to operate, and that can be safely opened and closed with one hand, strictly by feel without visual reference, thus facilitating the safe transport and consumption of beverages, especially hot beverages, by persons operating a motor vehicle or walking, or by visually-impaired persons.

It is a further object of the invention to provide a spill-resistant vent device to allow a closed cup to be knocked over or temporarily placed on its side without spilling any of its contents.

It is an object of the invention to provide a closure assembly with a footprint of minimum size on a lid to maximize the unobstructed area available for advertising or branding purposes.

Note: The major functional elements of the invention are described in some detail below to facilitate a complete understanding of the objects and advantages of the invention.

The invention provides a closure assembly that comprises a multi-function closure tab and cooperating parts of a lid.

The Lid

The lid comprises: a lid body of arbitrary topology that substantially seals the opening of a cup; a means for attaching said lid to said cup; an aperture for drinking or pouring the contents of said cup (herein called the drinking hole); a means for attaching the closure tab to said lid (herein called the vent base); and a vent hole (herein called the inner vent hole).

The lid is mated to a cup by a means appropriate for the cup. In the preferred embodiment, the lid is mated by snap-fit to an industry-standard beverage cup by means of an annular locking bead and flared skirt disposed below the lid body.

The lid may be embodied such that the lid body is essentially level with the top rim of the cup or alternatively such that the lid body is disposed above the top rim of the cup. The freedom to embody said lid as a “flat” or “domed” lid to accommodate various beverages and user preferences is an improvement over many known designs.

In the preferred embodiment of the lid, the vent base is positioned in the center of the lid to allow lids to be stacked efficiently without requiring any specific alignment. This is an improvement over other known reclosable lid designs wherein efficient stacking requires precise alignment of lids.

Furthermore, in the preferred embodiment of the lid, the central position of the vent base leaves the side of the lid opposite the drinking hole unobstructed so that said portion of the lid body is available for advertising or branding purposes. This is an improvement over known designs wherein a closure device significantly obstructs the surface of a lid.

In the preferred embodiment of the lid, the inner vent hole is included in the vent base.

It should be noted that the invention may be embodied in conjunction with any lid, and that the invention requires only a vent base and a drinking hole.

The Closure Tab

The closure tab comprises: a means for sealing the drinking hole (herein called the plug); a means for manipulating said closure tab to open and close the drinking hole (herein called the lifting tab); a means for attaching said closure tab to the lid (herein called the vent cap); a flexible means for joining the plug to the vent cap (herein called the connecting member); and a means for securing the plug away from the drinking hole when in the open position (herein called the plug holder).

In the preferred embodiment of the invention, the closure tab is secured to the lid by cooperatively mating the vent cap to the vent base. Said mating parts are so shaped and dimensioned that, in conjunction with the elasticity of the lid material, said parts are mechanically assembled and securely held together by press-fit. Said mating parts may have portions thereof shaped to induce proper alignment during the mating operation.

In another embodiment of the invention, the vent cap includes an annular bead or an annular groove that mates to a cooperating annular groove or annular bead of the vent base to securely assemble said parts by snap-fit.

In yet another embodiment of the invention, the closure tab is secured to the lid by bonding the vent cap to the vent base.

The Plug

The lid is provided with a drinking hole of arbitrary size, shape and placement to suit the nature of the liquid being contained. Said drinking hole is typically embodied on the lid body but may alternatively be embodied in a recessed portion of the lid body or in a raised portion of the lid body. This flexibility in providing a drinking hole is an improvement over many known designs wherein the size, shape and position of a drinking hole is constrained.

The plug has two alternative positions with respect to the drinking hole: namely the closed position wherein the plug seals the drinking hole, and the open position wherein the plug is secured away from the drinking hole by the plug holder.

In the closed position, the plug seals the drinking hole by cooperatively mating the plug to the drinking hole. The mating parts are so shaped and dimensioned that, in conjunction with the elasticity of the lid material, said parts when pressed together provide a fluid-tight seal.

In the preferred embodiment of the invention, the plug is embodied as a downwardly convex part that seals the drinking hole by being mated into the drinking hole. In said embodiment, the plug may be tapered, or may incorporate an annular groove or annular bead to facilitate the secure mating of the plug into the drinking hole to provide a fluid-tight seal.

In another embodiment of the invention wherein the drinking hole is raised above the lid body in the form of a spout, the plug may be embodied as a downwardly concave cap that seals the drinking hole by being mated over the said spout.

The Vent Device

The mating parts of the vent cap and vent base cooperate to provide a vented reservoir chamber between them (herein called the vent device).

A portion of the top surface of the vent base is concave or indented, and includes an inner vent hole. A portion of the vent cap may be convex or extended upwards, and includes an outer vent hole.

The vent reservoir is provided by the height differential between a portion of the top surface of the vent base and a portion of the bottom surface of the vent cap.

While steam or vapor may pass freely through the vent device, any liquid that splashes out of the inner vent hole will be contained in the vent reservoir, and will be induced by gravity and capillary action to fall back into the cup below, thus making the vent device spill-resistant. In the case of a cup placed temporarily on its side, any drops of the contained liquid that dribble out of the inner vent hole will be constrained in the vent reservoir until the vent reservoir is filled to the height of the outer vent hole, thus providing adequate time to return the cup to an upright position without any spillage of the contents. This functionality is not taught by the prior art and is an important improvement over all known designs.

The shape and volume of the vent reservoir and the size of the inner and outer vent holes will vary to suit the liquid being contained, and the degree of splashing produced in a specific application of the invention.

In another embodiment, the vent device is formed by mating of a separate part, formed in the manner of a vent cap, to a separate part of the lid formed in the manner of a vent base.

The Lifting Tab

The closure tab includes a lifting tab for manipulating said closure tab to open and close the drinking hole.

The lifting tab is provided by an outward extension of the closure tab beyond the plug.

The lifting tab is so shaped and positioned as to be easily grasped for the purpose of opening the drinking hole when in the closed position, or unlocking the closure tab when in the open position. This facilitates opening and closing the closure assembly strictly by feel without visual reference. This is an improvement over designs wherein the lifting tab lies on or close to the surface of the lid.

To facilitate efficient stacking of lids, the lifting tab may be induced to bend downward at the point where said lifting tab passes over the peripheral edge of the lid body. Said bending of the lifting tab is induced by a transverse “U” shaped groove, or by a thinned or narrowed portion of said lifting tab, or by a hole or slit punched in the lifting tab. This is an improvement over other known designs wherein a lifting tab must be formed close to a lid surface to allow efficient stacking, thus making it difficult to grasp such a tab.

The Plug Holder

The plug, when in the open position, is securely held away from the drinking hole by mating a suitably formed part of the plug to the plug holder. Said parts of the plug and the plug holder are of arbitrary placement, size and shape

The plug is secured to the plug holder in the open position by press-fit or snap-fit, by mating cooperating parts of the plug or a portion thereof to the plug holder.

In the preferred embodiment, the plug holder is provided by a suitably formed part of the vent cap. This provides a closure tab of minimum size and material, while providing a closure tab that is extremely easy to manipulate with one hand, without visual reference. The embodiment of the plug holder as part of the closure tab is not taught by the prior art and is a significant improvement over all known designs wherein a plug holder is embodied in the lid body or elsewhere.

In another embodiment, said plug holder is provided by a suitably formed part of the connecting member.

In the preferred embodiment, the part of the plug that mates with the plug holder is elongated with respect to the lengthwise dimension of the closure tab, or is otherwise shaped to facilitate mating said part of the plug to the plug holder. This ease of operation is an improvement over known designs wherein a plug holder requires precise alignment to function correctly.

The connecting member of the closure tab is induced to bend at a point such that the mating parts of the plug and the plug holder are brought into close proximity when the closure tab is manipulated from the closed position to the open position. Said bending of the connecting member is induced by a transverse groove formed in said connecting member, or by a thinned or narrowed portion of said connecting member, or by a hole or slit in the connecting member. This guided mating of the plug to the plug holder is a significant improvement over known designs wherein a connecting member is long, narrow and torsionally unstable, thus making alignment of a plug to plug holder difficult.

General

The main functions of the closure tab: namely to provide a spill-proof plug and to provide a spill-resistant vent device, may be embodied as separate components. In said embodiment, the separate components may be mechanically attached to the lid by means of suitably formed parts, or by thermal or adhesive bonding.

To suit esthetic and manufacturing preferences, the various mating parts described above can be embodied such that when any two parts are formed to mate with each other, that the first part is convex with respect to the second part, and the second part is concave with respect to the first part, or alternatively the first part is concave with respect to the second part, and the second part is convex with respect to the first part. This flexibility of embodiment has significant advantage over known designs wherein the topology of the functional elements is constrained.

The lid and closure tab are formed from suitable plastic material. Single-use disposable lids are typically vacuum thermoformed in a sheet of plastic material of essentially uniform thickness, while reusable lids or permanent lids are typically formed by injection molding.

A lid and closure tab may be formed separately or simultaneously. If formed simultaneously, said lid and closure tab may be formed such that when they are cut or punched out, they remain connected at one or more points. The lid and closure tab are then easily separated by the user for assembly by tearing them apart.

The invention provides a closure assembly that is easy and inexpensive to manufacture and assemble. The lid may be vacuum thermoformed as a nested array in a wide continuous sheet of suitable thermoplastic material. The closure tab may be simultaneously formed in the interstices of the lid array in areas that are normally scrap or “regrind”. The ability to simultaneously form lids and closure tabs, with very little additional material requirement, results in negligible incremental manufacturing cost over known simple lids. This provides a significant economic advantage over many known designs.

In the preferred embodiment of the lid, the parts of the lid that come into proximity when multiple lids are stacked together, are so shaped and positioned as to provide clearance between each other. Specifically, the locking bead and skirt for mating the lid to a cup, and the vertical projection of the vent device, and the vertical projection of the plug are such that the corresponding parts have clearance when stacked. Thus the closure assembly of the invention nests very well for efficient packaging.

In the preferred embodiment of the closure assembly the central position of the plug holder facilitates the single handed opening and closing operation of the closure assembly. Said operation is easily accomplished by grasping the lifting tab between one's thumb and index finger while grasping the cup rim using the base of one's thumb, palm and remaining fingers. This ease and flexibility of operation is not taught by the prior art and is an important improvement over all known designs.

While some of the individual improvements and advantages of the invention may be satisfactorily provided by known designs, the prior art does not teach any design that simultaneously provides all the numerous improvements and advantages recited.

BRIEF DESCRIPTION OF DRAWINGS

The invention will be described in greater detail with reference to the accompanying drawings, in which like numerals refer to like parts and in which different embodiments of the same parts are indicated by the same reference numeral with an alphabetic suffix.

FIG. 1 is an exploded perspective view of the closure assembly embodied in a lid illustrating the unassembled components of the closure assembly. FIG. 1 also illustrates the major named components of the closure assembly in the context of the preferred embodiment as:

The closure assembly is 1 and comprises 12. 13 and 20

The lid is 10 and comprises 11, 12 and 13,

The lid body is 11

The vent base is 12

The drinking hole is 13

The closure tab is 20 and comprises 21, 22, 23 and 24

The connecting member is 21

The vent cap is 22

The plug is 23

The lifting tab is 24

FIG. 2 is a perspective view of the closure assembly 1 illustrating the closure tab 20 in the closed position (sealed).

FIG. 3 is a perspective view of the closure assembly 1 illustrating the closure tab 20 in the open position (locked-back).

FIG. 4 is a top view of the lid 10.

FIG. 5 is a cross section exploded view along the line 2-2 of the closure assembly 1 of FIG. 6 illustrating the unassembled lid 10 and closure tab 20.

FIG. 6 is a top view of the closure assembly 1 with the closure tab 20 in the closed position.

FIG. 7 is a cross section view along the line 2-2 of the closure assembly 1 of FIG. 6 illustrating the closure tab 20 in the closed position.

FIG. 8 is a top view of the closure assembly 1 with the closure tab 20 in the open position.

FIG. 9 is a cross section view along the line 2-2 of the closure assembly 1 of FIG. 8 illustrating the closure tab 20 in the open position.

FIG. 10 is a detailed cross section view along the line 2-2 of FIG. 8 of the vent reservoir 30 through the closure tab 20 in the open position.

FIG. 11 is a detailed cross section view along the line 3-3 of FIG. 8 of the vent reservoir 30 across the closure tab 20 in the open position.

In the drawings, preferred embodiments of the invention are illustrated by way of example. Other further advantages and features of the invention will be apparent to those skilled in the art from the following detailed description thereof and the accompanying drawings.

It is expressly understood that the description and drawings are illustrative of certain embodiments of the invention, but the invention itself is defined by the accompanying claims.

DETAILED DESCRIPTION

Referring to FIG. 1, the closure assembly 1 comprises a closure tab 20 and cooperating parts of a lid 10, namely a vent base 12 and a drinking hole 13, said cooperating parts being formed in the lid body 11.

As shown in FIG. 1, the lid 10 comprises a lid body 11 in the form of an essentially planar disk that substantially seals a cup, and a drinking hole 13 for drinking or pouring out the contents of a cup, and a vent base 12 that cooperatively mates the closure tab 20 to said lid 10.

The lid 10 is mated to a cup by a means appropriate for the cup. In the preferred embodiment, the lid 10 is mated by snap-fit to an industry-standard beverage cup by means of an annular locking bead 18 and flared skirt 17 that project below the lid body 11. Said locking bead 18 and flared skirt 17 are sized and shaped for efficient stacking of lids 10.

As shown in FIG. 7, the lid 10 may be embodied such that the horizontal surface of the lid body 11 is essentially level with the rim of a mated cup, or alternatively such that said horizontal surface is embodied above the rim of a mated cup in the manner of a “dome” style lid.

The lid body 11 is provided with a drinking hole 13 of arbitrary size, shape and placement to suit the liquid being contained, and to suit aesthetic and manufacturing preferences. In the preferred embodiment, said drinking hole 13 is formed in a recessed portion of the lid body 11. In other embodiments, the drinking hole 13 is formed in the lid body 11, or in a raised portion of the lid body 11 thus forming a spout.

The lid 10 is provided with a vent base 12 of arbitrary size, shape and placement. In the preferred embodiment, the vent base 12 is formed by a vertical protrusion positioned in the center of the lid body 11. As shown in FIG. 1, the vent base 12 is generally cylindrical in form and in the preferred embodiment is tapered to facilitate mating with the vent cap 22. Said mating parts may have portions thereof shaped to induce proper alignment during the mating operation. The vent base 12 may be provided with an annular ring 16 or an annular groove for mating with a corresponding annular groove 26 or annular ring of the vent cap 22 to ensure the secure engagement of said mating parts.

The top surface of the vent base 12 is provided with a downwardly concave vent indentation 14. As shown in FIGS. 7, 10 and 11, said vent indentation 14 in conjunction with the mated vent cap 22 provides the vent reservoir 30 between them.

The lid body 11 includes an inner vent hole 15 located in the top surface of the vent base 12 at the bottom of the vent indentation 14.

As shown in FIG. 1, the closure tab 20 comprises: a plug 23 that selectively seals the drinking hole 13; a lifting tab 24 that is used to manipulate the closure tab 20; a vent cap 22 for attaching said closure tab 20 to the lid 10; and a connecting member 21 that connects the plug 23 to the vent cap 22.

The closure tab 20 is provided with a vent cap 22 that mates to the vent base 12 of the lid 10. As shown in FIG. 5, the mating surfaces of the vent cap 22 are shaped to cooperate with the corresponding surfaces the vent base 12. Said mating parts may have portions thereof shaped to induce proper alignment during the mating operation. The surface of the vent cap 22 may be provided with an annular groove 26 or an annular bead for mating with a corresponding annular bead 16 or annular groove of the vent base 12 to ensure the secure engagement of said mating parts.

As shown in FIGS. 7, 10 and 11, a portion of the horizontal surface of the vent cap 22 is shaped to provide a space between said surface and a portion of the horizontal surface of the vent base 12 when said parts are mated, thus creating the vent reservoir 30 between them.

The upper surface of the vent cap 22 is provided with the outer vent hole 25.

The vent reservoir 30 together with the inner vent hole 15 and the outer vent hole 25 comprise the spill-resistant vent device.

The shape and volume of the vent reservoir 30, and the size, shape and placement of the inner vent hole 15 and the outer vent hole 25 suit the liquid being contained and the degree of splashing produced by a specific application of the closure assembly 1.

The closure tab 20 is provided with a plug 23 for mating to the drinking hole 13. The plug 23 may be tapered or may be provided with an annular groove or annular bead that cooperates with a corresponding annular bead or annular groove of the drinking hole 13 to ensure secure engagement of said mating parts to provide a fluid-tight seal.

Referring to FIGS. 6 and 7, the upper or outer surface of the plug 23 or a portion thereof, is shaped for securely engaging the plug holder that in the preferred embodiment is provided by the upper or outer surface of the vent cap 22. The mating parts of the plug 23 and plug holder may be elongated with respect to each other, or be otherwise shaped to facilitate the mating of said parts.

The closure tab 20 is provided with a flexible connecting member 21 for connecting the plug 23 to the vent cap 22. Said connecting member 21 is induced to bend at a point such that the mating parts of the plug 23 and plug holder are brought into close proximity when the closure tab 20 is manipulated from the closed position to the open position. As shown in FIG. 5, said bending of the connecting member 21 is induced by providing in the connecting member 21 one of: a narrowed portion 27, a thinned portion, a transverse groove, a hole, and a slit.

The closure tab 20 is provided with a lifting tab 24 for manipulating the closure tab 20 to open and close the drinking hole 13.

The lifting tab 24 is formed by an outward extension of the closure tab 20 beyond the plug 23. Said lifting tab 24 is so shaped and positioned as to be easily grasped for the purpose of opening the drinking hole 13 when in the closed position as shown in FIG. 2, or unlocking the closure tab 20 when in the open position as shown in FIG. 3.

To facilitate efficient stacking of lids 10, the lifting tab 24 may be induced to bend downward at the point where said lifting tab 24 passes over the peripheral edge of the lid body 11. Said bending of the lifting tab 24 is induced by providing in the lifting tab 24 one of: a narrowed portion 27, a thinned portion, a transverse groove, a hole, and a slit.

In another embodiment, the vent device is provided by cooperatively mating a separate part, formed in the manner of a vent cap 22, to a separate part of the lid body 11 formed in the manner of a vent base 12.

To suit aesthetic and manufacturing preferences, the various mating parts described above can be embodied such that when any two parts are formed to mate with each other, that the first part is convex with respect to the second part, and the second part is concave with respect to the first part, or alternatively the first part is concave with respect to the second part, and the second part is convex with respect to the first part.

The lid 10 and closure tab 20 are thermoformed from suitable plastic material. Single-use disposable lids are typically vacuum thermoformed in a continuous sheet of plastic of essentially uniform thickness, while reusable lids or permanent lids are typically formed by injection molding.

The lid 10 and closure tab 20 may be formed simultaneously or separately. If formed simultaneously, the lid 10 and closure tab 20 may be formed such that when they are cut or punched out, they remain connected at one or more points. The lid 10 and closure tab 20 are then easily separated for assembly by tearing them apart.

In the preferred embodiment of the closure assembly 1, the parts of the closure assembly 1, which come into proximity when multiple lids are stacked together, are so shaped and positioned as to provide clearance between each other. The locking bead 18 and skirt 17 for mating the lid 10 to a cup, and the vertical projection of the vent reservoir 30, and the vertical projection of the plug 23, and the central placement of the vent device are shaped such that the corresponding parts nest efficiently. 

1. A closure device comprising: (a) a closure tab comprising: (i) a plug for selectively sealing an aperture in a lid by cooperatively mating said plug to said aperture to form a fluid-tight seal; (ii) a vent cap means provided with a vent hole, formed for cooperatively mating to a vent base means of a lid whereby a spill-resistant vent device is provided; (iii) a connecting member for flexibly attaching the plug to the vent cap means; and (iv) a plug holder means for selectively engaging and securing said plug, and (b) parts of a lid that cooperate with said closure tab, said parts of a lid comprising: (i) a vent base means provided with a vent hole, formed in a container lid for providing a spill-resistant vent device when mated cooperatively to said vent cap means; and (ii) an aperture, wherein said aperture may be selectively sealed by cooperatively mating said plug to said aperture to form a fluid-tight seal, wherein said closure device selectively seals said lid aperture, and provides said spill-resistant vent device, and provides said plug holder means for selectively securing said plug away from said lid aperture.
 2. A closure device of claim 1 wherein the connecting member includes a living hinge means for inducing said connecting member to articulate such that the plug is brought into close proximity with the plug holder means when the closure tab is manipulated to an alternative position wherein the plug is mated to the plug holder means, said hinge means being selected from the group consisting of: a narrowing of the connecting member, a thinning of the connecting member, a hole in the connecting member, a slit in the connecting member, and a transverse groove formed in the connecting member.
 3. A closure device of claim 1 wherein the plug has an attached lifting tab for manipulating the closure tab whereby a user can selectively open and close the aperture of the lid.
 4. A vent device comprising: (a) a vent base means provided with a vent hole, formed in a lid for providing said vent device when mated cooperatively to a vent cap means; and (b) a vent cap means provided with a vent hole, formed for cooperatively mating to a vent base means to form a fluid-tight seal, thereby forming a spill-resistant vent device between them, said vent device comprising a fluid-tight vented reservoir chamber, a vent hole in the vent base means and a vent hole in the vent cap means, whereby a sealed container may be placed briefly on its side without spilling any liquid contents of the container through said vent device.
 5. A vent device of claim 4 wherein a portion of the vent base means is concave with respect to a mated vent cap means or a portion of the vent cap means is convex with respect to a mated vent base means or both, whereby the volume of the vent device is increased, thereby increasing the spill-resistance of the vent device.
 6. A vent device of claim 4 wherein an alignment means is provided for facilitating the cooperative mating of a vent cap means to a vent base means.
 7. A vent device of claim 4 wherein a fastening means is provided for facilitating the cooperative mating of a vent cap means to a vent base means by snap-fit.
 8. A vent device of claim 4 wherein a plug is flexibly attached to the vent cap means by a connection member.
 9. A vent device of claim 4 wherein the vent cap means provides a plug holder means for selectively securing a plug to said vent cap means.
 10. A closure tab comprising: (a) a plug for sealing an aperture in a lid by cooperatively mating said plug to said aperture to form a fluid-tight seal; (b) a vent cap means provided with a vent hole, formed to provide a spill-resistant vent device when mated cooperatively to a vent base means of a lid; (c) a connecting member for flexibly attaching said plug to said vent cap means; and (d) a plug holder means for selectively engaging the plug to restrain said plug in an alternative position away from the original position of the plug, wherein the closure tab when cooperatively mated to a lid comprising a vent base means and aperture, provides a plug to seal said lid aperture, and in an alternative position of said closure tab, to restrain the plug away from said lid aperture by mating the plug to the plug holder means, and provides a spill-resistant vent device that allows a sealed container to be placed briefly on its side without spilling any liquid contents from said container.
 11. A closure tab of claim 10 wherein the connecting member includes hinge means for inducing said connecting member to articulate such that the plug is brought into proximity with the plug holder means of the closure tab when said closure tab is manipulated to an alternative position wherein the plug is mated to the plug holder means, said hinge means being selected from the group consisting of: a narrowing of the connecting member, a thinning of the connecting member, a hole in the connecting member, a slit in the connecting member, and a transverse groove formed in the connecting member.
 12. A closure tab of claim 10 wherein the plug or a portion thereof is elongated with respect to the plug holder means to facilitate the mating of the plug to the plug holder means.
 13. A closure tab of claim 10 wherein the plug includes an attached lifting tab for manipulating the plug between the open and closed positions. 